WASHINGTON – Democrats are accusing senior CIA officials of repeatedly misleading Congress, but Republicans say the allegations are just political maneuvering to protect House Speaker Nancy Pelosi.

The accusations come as lawmakers prepare to debate intelligence legislation — a bill President Barack Obama has threatened to veto.

Letters by the chairman of the House Intelligence Committee and other members of the panel say CIA Director Leon Panetta told Congress last month that senior CIA officials have concealed significant actions and misled lawmakers repeatedly since 2001.

Exactly what actions Panetta disclosed to the House Intelligence Committee on June 24 is unclear, but committee Chairman Silvestre Reyes, D-Texas, said the CIA outright lied in one case.

"These notifications have led me to conclude that this committee has been misled, has not been provided full and complete notifications, and (in at least one case) was affirmatively lied to," Reyes wrote to Michigan Rep. Peter Hoekstra, the committee's senior Republican. A copy of his letter was obtained by The Associated Press.

Reyes said in the letter that he is considering opening a full investigation.

Hoekstra on Thursday called Reyes' letter "one of the most bizarre episodes in politics that I've seen in my time here in Washington."

"It looks like they're working on the political equation," Hoekstra said on CBS' "The Early Show." "They're not trying to foster a bipartisan consensus on national security."

Panetta brought the matters to the committee's attention, CIA spokesman George Little said Wednesday.

"It is not the policy or practice of the CIA to mislead Congress. This agency and this director believe it is vital to keep the Congress fully and currently informed. Director Panetta's actions back that up," Little said. "It was the CIA itself that took the initiative to notify the oversight committees."

Seven Democratic members of the House Intelligence Committee sent a letter to Panetta on June 26 asking that in light of his disclosure he revise a statement he made in May to CIA employees that it was not CIA policy or practice to mislead Congress.

The cryptic letter and CIA statement came on the eve of a House debate on an intelligence bill. The debate is expected to revive a partisan argument that has raged on and off for months about whether Pelosi knew in the fall of 2002 about the CIA's use of waterboarding weeks earlier.

Waterboarding, which simulates drowning, is an interrogation technique the CIA used on three prisoners in 2002 and 2003. Obama has called waterboarding torture.

Much of the debate on the House intelligence bill is expected to be diverted into a discussion of what Pelosi knew about the CIA's harsh interrogation program and why, if she was briefed on it, she didn't formally object to it.

Republicans on the Intelligence Committee say the letters and Obama's threat to veto the legislation are cover-up attempts on behalf of Pelosi and what she knew and didn't do about "enhanced interrogation."

"The blatantly political nature of the Democrats' letters is revealed by their handling," said Jamal Ware, spokesman for Republicans on the committee, in a statement late Wednesday.

Pelosi told reporters in May she had not been informed that waterboarding had been used against terrorism suspects, even though it had been. When asked whether she was accusing the CIA of lying to her, she said, "Yes."

The CIA sent lawmakers a chart in May describing the 40 congressional briefings it gave on the interrogation techniques. But that document was found to include several errors, leaving in question exactly what Pelosi was told.

House Republicans oppose at least one provision in the intelligence authorization bill, and they have an unusual ally: the White House.

Obama's aides have said they will recommend he veto the bill if it includes a Democratic-written provision requiring the president to notify the intelligence committees in their entirety about covert CIA activities.

Under current law, the president is only obligated to notify the top Democratic and Republican leaders of the House and Senate and the senior Democratic and Republican members on each chamber's Intelligence Committee.